Hermetic motor driven fluid apparatus having improved insulating structure

Abstract

An improved electrical insulation structure is provided for a motor driven fluid apparatus having the compression and drive mechanisms within a hermetically sealed housing. The drive mechanism comprises a drive shaft operatively connected to the compression mechanism and a motor for rotating the drive shaft. The motor comprises a rotor fixedly surrounding the drive shaft and a stator assembly surrounding the rotor with a small radial air gap therebetween. The stator assembly comprises an annular magnetic core fixedly secured to the housing. The core has a plurality of axially extending slots and a plurality of windings, each having a plurality of coils formed by multiple turns of an enamel-coated conductor. The multiple turns of the conductor have side turn portions which are disposed within the axially extending slots and end turn portions which axially project from the slots and are generally disposed about the axial end surfaces of the core. The connection points between the windings themselves, and between the windings and conductor leads, are fixedly covered with a film of insulating material, such as epoxy resin. Alternatively, a portion of the surface of the housing is fixedly covered with a film of insulating material, such as aluminum oxide formed by anodization.

We claim: 
     
       1. In a hermetic motor driven fluid apparatus comprising a housing; a compression mechanism disposed within said housing; and a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism, and a motor operatively connected to said drive shaft for rotating said drive shaft, the improvement comprising: a portion of a surface of said housing being insulatingly covered by a film of an electrical insulation material.   
     
     
       2. The hermetic motor driven fluid apparatus of claim 1 wherein said housing is made of steel. 
     
     
       3. The hermetic motor driven fluid apparatus of claim 1 wherein said housing is made of an aluminum alloy. 
     
     
       4. In a hermetic motor driven fluid apparatus comprising a housing; a compression mechanism disposed within said housing; and a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism, and a motor operatively connected to said drive shaft for rotating said drive shaft, the improvement comprising: a portion of a surface of said housing being insulatingly covered by a film of an electrical insulation material;   said housing is made of an aluminum alloy; and,   said film comprising a film of aluminum oxide formed by anodization.   
     
     
       5. A hermetic motor driven fluid apparatus comprising an aluminum alloy housing: a compression mechanism disposed within said housing;   and a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism;   a motor operatively connected to said drive shaft for rotating said drive shaft;   wherein a portion of a surface of said housing is insulatingly covered by a film of an electrical insulation material, said film comprising a film of aluminum oxide formed by anodization; and   wherein said film has a thickness in the range of from about 15 μm to about 50 μm.   
     
     
       6. The hermetic motor driven fluid apparatus of claim 1, said electrical insulation material comprising a material selected from the group consisting of epoxy resin, urethane resin, silicone, phenol resin, urethane resin, butyl rubber, ethylene propylene rubber, chloroprene rubber, and nitrile-butadiene rubber. 
     
     
       7. A hermetic motor driven fluid apparatus comprising a housing; a stator assembly separate from said housing;   a compression mechanism disposed within said housing;   a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism; and   a motor operatively connected to said drive shaft for rotating said drive shaft;   wherein a portion of a surface of said housing is insulatingly covered by a film of an electrical insulation material;   wherein said electrical insulation material comprises a material selected from the group consisting of epoxy resin, urethane resin, silicone, phenol resin, urethane resin, butyl rubber, ethylene propylene rubber, chloroprene rubber, and nitrile-butadiene rubber; and   wherein said film is formed by powder coating.   
     
     
       8. The hermetic motor driven fluid apparatus of claim 7 wherein said film has a thickness in the range of from about 15 μm to about 50 μm. 
     
     
       9. A hermetic motor driven fluid apparatus comprising a housing; a stator assembly separate from said housing;   a compression mechanism disposed within said housing;   a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism; and   a motor operatively connected to said drive shaft for rotating said drive shaft;   wherein a portion of a surface of said housing is insulatingly covered by a film of an electrical insulation material;   wherein said electrical insulation material comprises a material selected from the group consisting of epoxy resin, urethane resin, silicone, phenol resin, urethane resin, butyl rubber, ethylene propylene rubber, chloroprene rubber, and nitrile-butadiene rubber; and   wherein said film is formed by dip coating.   
     
     
       10. The hermetic motor driven fluid apparatus of claim 9 wherein said film has a thickness in the range of from about 15 μm to about 50 μm. 
     
     
       11. The hermetic motor driven fluid apparatus of claim 6 wherein said film is formed by application. 
     
     
       12. A hermetic motor driven fluid apparatus comprising a housing; a compression mechanism disposed within said housing;   a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism; and   a motor operatively connected to said drive shaft for rotating said drive shaft;   wherein a portion of a surface of said housing is insulatingly covered by a film of an electrical insulation material;   wherein said electrical insulation material comprises a material selected from the group consisting of epoxy resin, urethane resin, silicone, phenol resin, urethane resin, butyl rubber, ethylene propylene rubber, chloroprene rubber and nitrile-butadiene rubber; and   wherein said film is formed by application and has a thickness in the range of from about 15 μm to about 50 μm.   
     
     
       13. A hermetic motor driven fluid apparatus comprising a housing; a stator assembly separate from said housing;   a compression mechanism disposed within said housing;   a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism; and   a motor operatively connected to said drive shaft for rotating said drive shaft;   wherein a portion of a surface of said housing is insulatingly covered by a film of an electrical insulation material; and   wherein said housing has an interior surface and an exterior surface, and wherein a portion of said interior surface is insulatingly covered by said film.   
     
     
       14. A hermetic motor driven fluid apparatus comprising a housing; a compression mechanism disposed within said housing;   a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism; and   a motor operatively connected to said drive shaft for rotating said drive shaft;   wherein a portion of a surface of said housing is insulatingly covered by a film of an electrical insulation material; and   wherein said housing has an interior surface and an exterior surface, and wherein a portion of said exterior surface is insulatingly covered by said film.   
     
     
       15. A hermetic motor driven fluid apparatus comprising a housing; a compression mechanism disposed within said housing;   a drive mechanism disposed within said housing, said drive mechanism comprising a drive shaft operatively connected to said compression mechanism; and   a motor operatively connected to said drive shaft for rotating said drive shaft;   wherein a portion of a surface of said housing is insulatingly covered by a film of an electrical insulation material; and   wherein said housing comprises a plurality of housing portions, which are releasably and hermetically connected to define a plurality of mating surfaces therebetween, and wherein at least a portion of at least one of said plurality of mating surfaces is insulatingly covered by said film.   
     
     
       16. The hermetic motor driven fluid apparatus of claim 1 wherein said compression mechanism comprises a mechanism selected from the group consisting of a scroll compression mechanism, a vane compression mechanism, a rolling piston compression mechanism, and an axial piston compression mechanism. 
     
     
       17. A method of electrically insulating a stator assembly, comprising the steps of: disposing the stator assembly within a housing; and   insulatingly covering at least a portion of the surface of the housing with a film of an electrical insulation material.   
     
     
       18. A method of electrically insulating a stator assembly, comprising the steps of: disposing the stator assembly within a housing;   insulatingly covering at least a portion of the surface of the housing with a film of an electrical insulation material;   wherein the housing is formed from an aluminum alloy; and,   wherein the covering step comprises anodizing the housing to form a film of aluminum oxide.   
     
     
       19. A method of electrically insulating a stator assembly, comprising the steps of: disposing the stator assembly within an aluminum alloy housing; and   insulatingly covering at least a portion of the surface of the housing with a film of an electrical insulation material, said covering step comprising the steps of:   anodizing the housing to form a film of aluminum oxide; and   forming the film to have a thickness in the range of from about 15 μm to about 50 μm.   
     
     
       20. The electrical insulation method of claim 17 wherein the electrical insulation material is a material selected from the group consisting of epoxy resin, urethane resin, silicone, phenol resin, urethane resin, butyl rubber, ethylene propylene rubber, chloroprene rubber, and nitrile-butadiene rubber. 
     
     
       21. A method of electrically insulating a stator assembly, comprising the steps of: disposing the stator assembly within a housing;   wherein said stator assembly is separate from said housing; and   insulatingly covering at least a portion of the surface of the housing with a film of an electrical insulation material, the electrical insulation material selected from the group consisting of epoxy resin, urethane resin, silicone, phenol resin, urethane resin, butyl rubber, ethylene propylene rubber, chloroprene rubber, and nitrile-butadiene rubber, said covering step comprising the step of:   forming the film by powder coating.   
     
     
       22. The electrical insulation method of claim 21 wherein the covering step further comprises forming the film to have a thickness in the range of from about 15 μm to about 50 μm. 
     
     
       23. A method of electrically insulating a stator assembly, comprising the steps of: disposing the stator assembly within a housing;   wherein said stator assembly is separate from said housing; and   insulatingly covering at least a portion of the surface of the housing with a film of an electrical insulation material, the electrical insulation material selected from the group consisting of epoxy resin, urethane resin, silicone, phenol resin, urethane resin, butyl rubber, ethylene propylene rubber, chloroprene rubber, and nitrile-butadiene rubber, said covering step comprising the step of:   forming the film by dip coating.   
     
     
       24. The electrical insulation method of claim 23 wherein the covering step further comprises forming the film to have a thickness in the range of from about 15 μm to about 50 μm. 
     
     
       25. The electrical insulation method of claim 20 wherein the covering step comprises forming the film by application. 
     
     
       26. A method of electrically insulating a stator assembly, comprising the steps of: disposing the stator assembly within a housing; and   insulatingly covering at least a portion of the surface of the housing with a film of an electrical insulation material, the electrical insulation material selected from the group consisting of epoxy resin, urethane resin, silicone, phenol resin, urethane resin, butyl rubber, ethylene propylene rubber, chloroprene rubber, and nitrile-butadiene rubber, said covering step comprising the step of:   forming the film by application to have a thickness in the range of from about 15 μm to about 50 μm.   
     
     
       27. The hermetic motor driven fluid apparatus of claim 5, further comprising a plurality of external power conductor terminals fixedly secured to the housing and a plurality of conductor leads electrically connected between the motor and the plurality of external power conductor terminals, wherein at least one of the connection points between the plurality of external power conductor terminals and the plurality of conductor leads is insulatingly covered by the film of an electrical insulation material. 
     
     
       28. The method of claim 27, wherein a plurality of external power conductor terminals is fixedly secured to the housing and wherein a plurality of conductor leads electrically connects the stator assembly to the plurality of external power conductor terminals, the method further comprising the step of insulatingly covering at least one of the connection points between the plurality of external power conductor terminals and the plurality of conductor leads with the film of an electrical insulation material.